Generally, an ink jet recording apparatus includes a maintenance mechanism for maintaining ink ejection performance. In one known maintenance mechanism, after covering a nozzle surface of an ink jet head with a cap, a negative pressure suction pump is operated to cause a negative pressure suction force to act on the nozzle surface of the ink jet head, thereby recovering waste ink from the ink jet head side.
For example, Patent Document 1 discloses a structure comprising a cap for covering a nozzle surface of an ink jet head, a negative pressure suction pump connected for fluid communication to an ink drain port of the cap through a connecting tube, and a waste ink tank connected for fluid communication to the negative pressure suction pump for recovering sucked waste ink.
Also, an ink jet printer disclosed in Patent Document 2 comprises a printing head having a plurality of nozzles, a cap having an opening in common to the plurality of nozzles of the printing head and a plurality of suction ports, the opening being brought into close contact with nozzle surfaces to form an enclosed space, at least one suction pump for sucking ink from the plurality of nozzles through the plurality of suction ports of the cap, and ink flow passages for connecting the suction ports of the cap to the suction pump, wherein the ink is jetted from the nozzles of the printing head to print dots on a medium, and the opening of the cap is brought into close contact with the nozzles to suck waste ink when power is turned on or when an occasion requires.
Further, Patent Document 3 discloses the following feature. By providing a plurality of suction ports in a suction cap and controlling the opening/closing operation of each of valves disposed in respective passages communicating with the suction ports, ink can be properly filled in all channels when the ink is initially introduced, and air bubbles can be efficiently removed from the channels near ends of a head in which the air bubbles tend to reside, when a periodic purge is performed.    Patent Document 1: Japanese Patent Laid-Open No. Hei 7-81089    Patent Document 2: Japanese Patent Laid-Open No. Hei 7-304191    Patent Document 3: Japanese Patent No. 3800855